1. Field of the Invention
The present invention relates to an electromagnetic relay having a remarkable silencing effect during an activating mode and a releasing mode. Such a relay is used particularly in an automobile, an air conditioner, and the like.
2. Description of the Related Art
An electromagnetic relay is conventionally comprised of a yoke, an armature rotatably coupled with an end of the yoke, a movable contact spring associated with the armature, and a core having a bottom fixed to another end of the yoke and a top opposing the armature. Also, at least one movable contact is mounted on the movable contact spring, and a corresponding stationary contact is provided. When a winding wound on the core is excited to activate the relay, the armature is attracted by the core and a sound is generated due to the impulsive force of the movable contact against the stationary contact when making contact therewith and the impulsive force of the armature against the top of the core. In the prior art, to reduce this sound, a helix spring is provided on the top of the core (see: Unexamined Japanese Utility Model Publication No. 61-75042), which will be later explained in detail.
In the above-mentioned prior art, however, since the load of the helix spring is added to the entire load of the relay, the relay load is increased, and therefore, when the attraction force of the core is definite, the margin of operation is reduced, and further, the contact force of the movable contact against the stationary contact, which in this case is a make contact, is reduced, thus reducing the performance of the operation. Further, the helix spring is not intended to reduce a sound due to the impulsive force of the movable contact against the stationary contact, which in this case is a break contact, when the winding is non-excited to release the relay.